Alligator shear



Feb. 27, 1945. L HERCIK 2,370,311

ALLIGATOR SHEAR I Filed Jan. 26, 1944 2 Sheets-Sheet 1 1 10 L. Haze K Maia Feb. 27, 1945. L L HERGK' 4 2,370,311

ALLIGATOR SHEAR Filed Jan. 26, 1944 2 Sheets-Sheet 2 //Vl/EN7'0R 1A0 L HERC/K Z QZMM 6%,

Arra /vex Patented Feb. 27, 1945 ALLIGATOR SHEAR Lad L. Hercik, Lakewood, Ohio, assignor to The Hill Acme Company, Cleveland, Ohio, 2!. corporation of Ohio Application January 26, 1944, SerialNo. 519,712

9 Claims.

This invention relates to machinery for shearing metals and particularly to open throated lever type shearing machines of the class, generally known as alligator shears.

Machines of this class are used in steel mills, forge shops, scrap yards, and other places, for shearing fiat, square and round bars. angles, rails and other shapes. These machines are usually made with avery heavy elongated bed provided, intermediate its ends, with a king pin upon which a heavy lever arm is mounted. This lever arm is fitted at its forward end with a shear. blade adapted to cooperate with a similar blade mounted in the forward end of the bed. The rear end of the lever arm is connected with, power mechanism of any convenient type for oscillating or actuating the lever arm to rock about the king pin as a pivot, thus moving the shear blade on the lever arm into shearing engagement with the blade on the bed.

The present invention is particularly directed to improvements associated with the king-pin of a shearing machine of the above type.

In machines of this type heretofore built, frequent failures have occurred either in the king pin itself or in the mounting of the king pin. King pins in this type of shears have usually been mounted in 'a pair of spaced bearings formed in ears or bosses integral with the bed, and the lever has been mounted on the pin between these spaced bearings. A stationary shear blade has been mounted on a support integral with and extending forwardly from one of the bearings in the bed and cooperating with the shear blade mounted on the adjacent face of the lever arm.

When a steel bar is sheared there occurs a very heavy side thrust, tending to movethe lever away from the stationary shear blade. This thrust has always, so far as I am aware, been transmitted by various devices, to that ear on the bed laterally spaced from the stationary shear blade that is, to that car located on the other side of the lever arm from the stationary shear blade. This has resulted in a tendency of the spacedear to tilt outwardly causing a slight but serious misalignment of the bearing with the pin at each cutting stroke and frequently, when a heavy bar is cut, imposin a bending load on the spaced ear sufficiently heavy to cause'a fracture resulting in breaking the ear oii the bed of the shear.

. Heretofore various devices have been-associated with king pins for laterally adjusting the lever with respect to the stationary blade and for taking up wear, which devices have been expensive to produce, complicated inconstructionand difiicult to adjust.

The hereinafter described alligator shear king pin construction and 'mounting have been developed to eliminate the above defects inherent in present constructions.

It is accordingly a primeobject of this invention to produce a king pin construction and mounting, in a. shear of this type; which over-- comes-the imposition of heavy axial thrusts'upon that king pin supporting boss on theside of the a shear spaced from the stationary shear blade.

1 either of the ears supportingthe king pin bearings. I

It is a further object of this invention to produce a construction in which no loads are applied :to the bearing bosses which tend to tilt the bosses and in which the loads on the bearings are limited :to radial loads.

' It is a further object of this invention to produce a king pin mounting which does not require any adjustable devices for laterally positioning the shear lever arm or for taking .up axial wear.

It is a further object of thisinvention to produce, a king pin which can readily beassembled or replaced and in which radial and axial bearings can readily be repaired or renewed.

, Aifurther understanding of the construction and operation and of the manner in which the novel features of this invention effect the'above and further objects, will become apparent from the following detail description and the annexed drawings, which set'forth certain means embodying this invention; such disclosed means constituting, howevenbut one of the forms in which the principle of this invention may be applied. Referring to the annexed drawings:

Fig. 1 is a right side elevation of an alligator shear embodying this invention, the shear being shown in the closed :position, anopen position of the forward end of thelever arm being shown fragmentarily in dot and dash lines.

Fig. 2 is an enlarged front elevation of the alligator shear shown in Fig.-1,t hisview being taken from a position facing the jaws at the shearing Fig. is a similarly enlarged plan view of the front end of the shear shown in Fig. 1, this view parts which are sheared off in the operation of this machine. The left face of the upwardly extending portion 1 flares sidewardly in a rearward direction, as indicated at l3, to form a substantial integral and strong connection with the boss 5.

Bosses 5 and 6 are each formed with a bore indicated, at l5 and I6 respectively. These bores extend thru thebosses in a direction transverse tothe. length of the shear bed and are axially alined with each other and the axis of these bores is located approximately in line withthe top of the stationary sheanblade 8 in the embodibeing partly broken away on the planes indicated 5 by lines 5, 5, in Fig. 1. a

This alligator shear illustrated ;f0i' the P -1 1 .5?

of disclosing the present invention is elongated in its general conformation andis provided inter-g,

mediate its ends with pivot mechanism for rock ing or oscillating a shearing lever arm about. ai. 2

horizontal transverse axis, shearing mechanism being provided at the front end of thejn'rachine and suitable power mechanism being provided at th rear mage; the machinefor the p rpos oscillating orflrockingthelever, arm about the pivot mechanism. '1.

'Ifh.:main frame of this improved alligator shear comprises a preferably elongated bed indicated atLI bed is of hollow ribbed'construction and. formed with a flanged base portion 2 adapted torest on' a suitablev permanentfounda tion or. portable support depending. upon the size. of the shear and the purpose for which the shear is to be. used. For purposes of connecting the shear tothe foundation or. support suitable openings 3 are provided to accommodate bolts or other connecting means. i a I Preferably integrally formed with the base portion is a side wall construction 4 of box conformation which extends, in the embodiment disclosed, for substantially more than; one half of the length of the bed, Adjacent theforward end and pref-- erably integrally formed with the side wall con struction 4 are a pair of bosses 5 and 6 transversely.smroed,v the boss 5 being located atthe left sideiof themachine. as. viewed in'Figures 2 and 3. and theL bDSSF6=bein8-1OCBlZEd at the right side. of the machine. 1 a

Formed at the front of the bed andpreferably. integrally. cast: withthe boss 5 is a portion 1, this portion extending upwardlyfrom the base 2 and forwardlyfrom. theboss 5, and being. disposed on the left side of the bed, that is. on the same side. ofthe bedas the boss 5. This portion-lserves as a support for a stationary shear knife or shear edges at the top andbottom of each side'in order that the blade may be successively reversed and invertedwhen the edges become dull; This blade is secured: in place by means of'a plurality ofcountersunk head-bolts II, as clearly appears from Fig.3-of'- the drawings. The lower'portion of the left side of;the' upwardly extending portion' 1; is flared sidewardly and'downwardly, for

the purpose of providing strength to resist lateral thrusts and'in order to distribute the vertical load incident to the shearing action. The right fade of the portion 'lfiares sidewardly and-downwardly with a curved surfacesubstantially from the face of the stationaryblade, as indicated-at l2, to provide strengthand to afford clearance for the nient disclosed.

Mounted in the bores l5 and, 16 are removable sleeves or bushin ll and 3 each formed, on that end away from the center of the bed, with a .radially outwardly extending flange indicated at l9 and 20, respectively. The bushings n and la,

' are provided with liners 2| and 22, respectively,

preferably formed of antlfriction material, and provided to serve as bearings fora horizontal pivot pin or king pin, hereinafter to be described. The flanged bushings I1 and I8 are. secured to th bosses 5 and 6 respectively, by means of a pluralityv .Qf cap screws 23. The outer faces of the flanges I9 and 2!! of these bushings are accu-' rate'ly machined. to serve as thrust bearing sur faces; as will be explained.

Rotatably mounted in the bearings formed by the liners 2i and 22 is a king pin 24 of special conformation, best illustrated in Figures 4 and 5 As will appear from the drawings, the king pin .{4 is formed with two jo urnal portions 25 and 28. engaging the bearing surfaces of the liners 2 l and 22, respectively. Intermediate these journal portionsis a central portion 21 slightly larger in diameter than the joumal portions 25 and 2B. Atthe right side of the central portion 21, as' viewed in Fig. 4, is a still further enlarged pref.- erably integral annular collar or shoulder 28. The portions 21 and 28 are disposed between the a spaced bosses 5 and 5, as clearly appears from the drawings.

i The annular shoulder portion 28 is preferably slightly spaced from the inner face of th adjacent boss 6 and hence from the bushing It and liner 22, "which space is clearly indicated at 25,

in Fig. 4;

. Mounted upon the portions 21 and 28 of the pin zus a shearing arm or'lever arm 30 formed with a hub intermediate its ends. The hub 3| is formed with a bore 32' accurately conforming to the contour of the portions 21 and 28 of'the king pin, the bore 32 being formed with a shoulder indicatedtat 33 engaging the left face of the collar 28', thus preventing axial movement of the lever arm 30in a right hand direction (Fig. 4) relatively to the king pin 24;.

In practice itis preferable to shrink the lever arm on the king pinin order to insure the lever arm against becoming loose on theking pindue to the severe and heavy loads to which shears of this type are subjected."

The lever arm extends both forwardly and rearwardly from the axisof the king pin 24' and is necessarily of heavy construction in order that the lever may resist the heavy stresses imposed thereon; and may be'of cored, hollow 'or I -beam crcss-section in order thatunnecessary weight: may be eliminated. The forwardly extending portion 34 ofthe lever armservesas a support for the movableshear blade 35. In order to accomm'odate this shear bl'ade 35, a machined seat is formedln the-portion 34,- said seat'comprlsing a'horizontal face 36 and a vertical face 31. The shear blade 35 is preferably a duplicate of the stationary shear blade 8 for the'sake of interchangeability and is formed with cutting edges at the'top and bottom of each side. As in the case of the stationary blade 8, the movable blade 35 is held in place by means of a plurality of countersunk head bolts 38.

' The forwardly extending portion 34 of the lever arm 30 is flared upwardly toward a point above the hub 3| of the lever to assure strength to overcome the vertical resistance to shear and is flared laterally in the direction toward the hub 3| to resist the-lateral thrust and twist which is imposed upon the lever arm 30 during the shearing action. The lever arm immediately above the blade 35 is formed to provide clearance for the parts which are being sheared.

1 It will be evident, particularly from Fig. 2, that the right face of the lower stationary shear blade 8 and the left face of the upper shear blade 35 are substantially in the same plane, the proximity of these faces to each other being determined primarily by the dimensions and character of the parts to be sheared.

The lateral thrust resulting from and incident to the shearing action is very substantial and this thrust is transmitted-by the lever arm to the king pin 24 which thus imposes a very substantial thrust in an axial direction on the king pin. In order to resist this thrust and in order to prevent excessive wear resulting from this thrust, a special construction is provided at the scale, etc. This cap 50 may be of any desired conformation to suit the parts to be enclosed and is, for purposes of illustration, shown in the drawings as of generally truncated conical shape forming a cavity adapted to serve as a lubricant reservoir. This cap is formed with a circular flange 5| provided with a series of openings to receive the cap screws 23 which pass thru registering openings in the flange [9, thus serving to fix both the cap 53 and the bushing l5 to the boss 5. A suitable filling opening closed with a plug is formed adjacent the top of the cap 50 for the purpose of supplying lubricant to the reservoir thus formed.

At the end of the pin 24 opposite to the thrust collar end, that is at the right end as viewed in Fig. 4, the pin 24 is formed with a thread 55 upon which is mounted a threaded split collar or nut 56 which may be adjusted axially along the pin 24 by rotating it on the pin until the nut engages the outer face of the flange 20 of the bushing [8 as tight as may be desired, whereupon'the collar may be clamped in position by tightening a bolt 51. This collar 56 is provided primarily for the purpose of taking up any slack or axial loose play during assembling or to take up such loose play as may result from wearbetween the collar 45 and the face of the flange I9. This nut 56 accordingly prevents the lever arm 33 from moving left end or stationary shear blade end of the king pin 24, which construction will be understood by reference to Figures 4 and 5. The king pin 24 is formed, at the end adjacent the boss 5, with a relatively wide groove 45 defined by an inner shoulder 4| substantially radially alined with the face of the flange l9 and an outer shoulder 42, and an intermediate neck portion 43 smaller in diameter than the adjacent portions of the pin 24. The terminal portion of the shaft indicated at 44 is of a diameter substantially greater than the diameter of the neck portion 43 but slightly less than the diameter of the journal portions 25 of the pin.

Snugly seated in the groove portion 40 is a split collar formed of two halves secured together by bolts 46. The width of this collar is preferably substantially identical with the width of the groove 40 and the bore of the split collar is preferably machined to form a clamping fit on the neck portion 43 and'the inner face of the collar is accurately machined to form a smooth seat for engagement with the face of the flange l9. This collar 45, being securely clamped on the shaft, oscillates with the shaft, and the axial thrust of shaft, incident to the shearing action of the blades 8 and 35, is transmitted to the collar 45 by the enlarged terminal portion 44 and the collar in turn transmits this thrust to the face of the flange I9 of the bushing l5.

The area of contact between the inner face of the collar 45 and the face of the flange I9 is preferably so proportioned that the intensity of the thrust pressure is well within the maximum for'which the engaging metals are designed. In order, however, that these engaging surfaces may be assured of long life and minimum wear I provide for their continuous and effective lubrication. For this purpose I have provided a special to the left as viewed in Fig. 4.

In order to insure proper lubrication of the engaging surfaces of the collar 56 and flange 20 a cover'cap 58 formed with a. flange 59 is provided, this cap being provided with a plugged opening for lubricant and being held in engagement with the flange 20 and secured to the boss 6 by means of cap screws 23 in the manner similar to that described with reference to the cap 45, flange l9 and boss 5.

While lubricant is supplied to the bearings 21 and 22 and journals 25 and 26 from the oil reservoirs formed by the cover caps and 58, additional lubricating wells 60 and 6| are provided in the bosses 5 and 6 for the purpose of supplying lubricant directly to the pin bearings and journals.

The oscillation or rocking of the lever arm about the axis of the pin 24 may be effected by any suitable mechanism which is preferably power actuated. Since this mechanism forms no part of this invention per se it need not be described in detail. One type of this mechanism is, however, disclosed in general form in Fig. 1.

Referring to this figure, indicates the motor supported on a bracket extending upwardly from the side walls 4 of the bed I. Upon the shaft of this motor is mounted .a V-belt pulley 66 driving a plurality of laterally spaced V-belts 61, these belts engaging the periphery of a fly wheel 68 mounted on a shaft 59 which is, in turn, ro-' tatably supported in the bed I. Mounted on this drive shaft 69 are one or more pinions 10 engaging one or more gears H which in turn are mounted on a crank shaft 12. This crank shaft is mounted on suitable hearings in the bed I and is formed, preferably intermediate its ends and in line with the longitudinal median plane thru the lever arm 30, with a crank 13. The crank cover cap 50 to enclose the collar 45' and the associat'ed parts, not only for applying lubricant but also-to keep out foreign elements such as dirt,

-It will be evident that the actuation of the mo or 65. causes the crank shatt t2 toi rotate: which in turncauses; the. lever. amrtoi oscillate or; rock ahoutthekinmpin- 24. As airesult; or this: oscillation-, the movable shear: blade; 35; swings angularly upward-hp from the closed position, shown. in the drawings; to an open positiom. shown. partly" in broken lines in. Fig. 1. anotthen again moves; to! the closed; position shown in: 11111 lines: in-the drawings, during which downward: 111031.82- ment. the shearing action takes: place. This. opening, and closing oi: the shear blade may be continuous; or. the operation may be controlled-e by; thezoperatorin whichievent. the: shear is-normally in an open position.

The. shearing: action, as welt knowm to: those skilled. in. this: art,, produces severe; side; thrusts: applied to:- theshear blades: in. opposite: directions; at. the; area of; shear:. Reference. tco Figures 4. and 5K will. disclose that the: lateral thrust: imposed on. the: movablev shear. blade 35. is trans.- mittedithru. the; lever: arm 30; to; thev king pin. 24 and thence to; the collar 45 which in; turn, transmits; the thrust to; the; face. of the flange I 9: of: the: bushing H in the boss 5;. Theal'ateral. thrust; acting. in the opposite. direction on. the stationary shear blade, 8: is, transmitted thm' the upwardly extending: portion. h or: the: bed tOi the boss I.- and: thence to: the flange. lit which; reacts. with the thrust transmitted by theinnentacezot' the collar 45. It will therefore: appear that; this; thrust: is transmitted in two directions from the area-.01: shear: to. theflange; I! on thecouter; face 01': the, boss; 5 in azdirect andiselfi containedcman... her; It: will also be; evident that the: thrust of the: stationary blade tends. to move the. boss 5' outwardly in: an axial direction and that. the thrust, of: the movable blade tends to"- moves the boss:& in an1inwarddirection',.these thruststhere. fore tending to counteract each other alongiaalinesubstantially coaxiah with the boss 51 and the P111124.

Itwill also be evidenizthatthedournalizfl is free' tdmove; axially; with respect tozthe bearing 22:

mounted in the boss: 6.; and thatno axial; thrust will; be: imposed; on the bosstgas a resultof the transverse thrust incident to shearing. It isxtou be; understood}. however;, that; a; clearance indicated: at. 29' must: be; maintained. between; the: shoulder: 28; on: the pin: 24;. and: between. the-hub 34.: of. thee lever arm on; the one; hand; and: the; bearing 22;, and' the-bushing: lflian'd the: assooi atedl boss-,- 6., cm theother'hand; if: the; 8% is to bemaintainedz: free. oi axial-thrust.

It will be understood that; the: originalrtiliokness of the; shear bladesshould: be selected: ap'-= proximately: to suit the: relative POSitiOl'lSiOfi the: sheen blade. seats on. theileverarm and on; the: bed, asfixed by the. positions; of:. the collar: 85, ofzthe-iace of the; flan e: larandioi. the=zlocatiom of, the-lever. arm: on thepin 2.4:. If, subsequently; wear shouldioccur on the collarrflsorrflangecllrorv if. the; shear blades: should be 1reducedlin2wldtl'1; as-fa result. of grinding, shims; onpacking 'mayrbes, interposed between one orcbothotthasheanblades'z and:; their respective: vertical; seats as suggested; at. 8c, and 3.5a,- respectivelsn. Thor blades: may: also be. adjusted. toward;- each; other in; axvertical 5 direction by insertingshims.betweenrshear:blades; and; their horizontal; seats .ior: which; purposea the; holes: in: the 1 bed. and =leverarm-thrm which the? bolts H. and: 3m pass-,2. are. slotted-4 hit a vertical;

direction; l

Thezpreferred-iprocedure 1 in 1 installlngjheskinai pin 24 in this alligator-:shearwhenitherleven arrm amen..-

to=the installation-Jot the king D111}. theiond' covers 5m and, 58! are: not attached and; the bushings-'41 and; W are notinsertedi in: the/bed; likewise. when: the lever is; to be: shrunk on: thepin N its bore 32: is machined slightly smaller thamthe-diametoa otthe portions 2 and it oh the:k.lng:p1n'. Umden' these conditions thelever arm 30: la matted between the bosses 5 and S withttherbore 3 sub-- stantially alined with the bores l5! and lo- 015 the bosses. 5 and- 6; the hub it of the lever having been heated. either prior to the. positioning referred to-or subsequent-thereto; When the hub 3.1 has been heated; sulllciently to expand it w the desired-extent the king: pin-.20 without the: split. collar 45;, is inserted from left; to right thru thev bore l-G; thruuthe bore' and! thru the bore l5: until the: collar 2E engages the shoulder a whereupon the lever'isipermitted to coot until it engages the portion. 21: of; the pin and collar in shrinking: relation; After the parts have cooled sufficiently thebushings I! and: II with" their liner-s1 and. 22: are inserted in the bores lland l tresnectivelw. which-operation ispreferablyper formed with pressure; After the bushings are properly seated in the bosses 57' and 6; the spllb collar. 45 and the clamp: nut. 55- are applledi to aor.

.gressively force the: bushings outwardly away from the bosses 5 and 6.- Repairs-may 'then be made: either by renewing; the liners or by insert-- ing shims: between. the flanges I8: and the. outer facesrofi thebossesz 5, as;mey, be required, and by" the. replacing of the: bushings; tothe endi that. the machine may be placed inits original: con-- ditiom.

It will be evident that the herein discloeedalli gator shear construction eliminates: the impolitioniofrdangerousxunbalancedrthrustson"the bent ingclocated onthat: side of the lever arm oppow site: the; fixed shear: blade; produces a-oonatrw. tion in whicl'rthezopposed lateral-thrusts incident,- to the: shealingzaction .015- the blades are self con tainedand counteract: each'otherthru the instrumentality' of that; bearing. boss. andassociated:

parts located' om the: same: side of." the:shear as the stationary shear: blade; produces I a king! pinuconstruction in whichri the;radiairand thrust bearings: canzreadily be repaired: or; renewed; and: which; othemse fillfillsr the: objects of this; in ventioniset fortlizat. the beginning-or these sp'eclflacations.

While the hereirnv described: disclosures 111m trates this.-.invention-. embodied its a shear: of i the low knife:type;.' that'is, actype. inxwhich-theshearing. plane isl substantially." in line withthm "(is to. beshrunk onr.tho'.-pm ,-zismmfollowszzPrlor 7 hand, as shown; instha. mingm ll fiaxis: of: the king; pim. it is. evident-- thatithiayln ventioni may; hex-applied; with equal: or advantage; z to; mshear: of the high .kniie'type iniwhichthe bladessare: raised sothat theshean' ingq'plane is-located: atsubstantiali distance abovetheraxis of melting pin thiszplanezbelng-irr'malm cases: in linemvith'. the tomof: the: bearing: boiuly Thisiimproved shear may be-bullt either depending primarily upon the location in which the shear is to be used, the selection of the hand of the machine being governed by accessibility and by conditions limiting the feeding to a particular side.

It should be noted that in the broader concepts of this invention the lever arm need not be rotatably fixed to the kind pinbut might be pivotally supported on the king pin which inturn might be rotatably fixed in the bosses of the bed.

Many other modifications of this invention and its application will naturally occur to those skilled in this art and the present disclosure should therefore be considered typical only, and

I desire not to be limited to the exact constructions shown and described.

What I claim is:

1. In an alligator shear in combination, an elongated bed, a pair of transversely spaced bosses disposed intermediate the front and rear ends of the bed, a pin supported in the bosses, a lever arm axially fixed intermediate its ends on the pin between the spaced bosses and adapted to oscillate about the axis of the pin, a stationary shear blade mounted on a portion of the bed extending forwardly from and fixed to one of the bosses, a shear blade mounted on the forwardly extending portion of the lever arm adapted, when the lever is oscillated, to cooperate with the stationary blade in shearing relation, and power means adapted to oscillate the lever arm, the pin and the boss to which the forwardly extending portion of the bed is fixed being provided with interengaging axial thrust means adapted to transmit to said boss the transverse thrust incident to the shearing action of the blades.

2. In an alligator shear, in combination, an elongated bed, a pair of bosses rising from opposite sides of the bed, a king pin supported in the bosses and mounting a lever arm for pivotal movement about the axis of said pin, cooperating shear blades mounted on the bed and the lever arm respectively and adapted to impose axial thrust on the pin during shearing, and shoulder means cooperating with the pin and one of the bosses to receive said axial thrust and transmit the same inwardly through said one boss toward the center of the bed.

3. In an alligator shear in combination, an elongated bed, a pair of transversely spaced bosses disposed intermediate the front and rear ends of the bed, a pin supported in the bosses, a lever arm axially fixed intermediate its ends on the pin between the spaced bosses and adapted to oscillate about the axis of the pin, a stationary shear blade mounted on a portion of the bed extending forwardly from and fixedly connected with one of the bosses, a shear blade mounted on the forwardly extending portion of the lever arm adapted, when the lever is oscillated, to cooperate with the stationary blade in shearing relation, power means adapted to oscillate the lever arm, and shoulder means provided on the pin adapted to transmit, to that boss fixed to the stationary shear blade mounting, the entire transverse thrust incident to the shearing action of the blades, the pin being free to move in the direction of the thrust in the other of the bosses.

4. In an alligator shear in combination, an elongated bed, a pair of transversely spaced bearing bosses disposed intermediate the front and rear ends of the bed, a pin rotatably supported in the bosses, a lever arm fixedly mounted, intermediate its ends, on said pin between the spaced bosses, a stationary shear blade mounted on a portion of the bed extending forwardly from and fixedly connected to one of the bosses, a shear blade mounted on the forwardly extending portion of the lever arm adapted, when the lever is actuated, to cooperate with the stationary blade in shearing relation, power means adapted to actuate the lever arm, and a thrust collar engaging the bearingboss located on that side of the lever arm on which the stationary blade is located, said thrust collar being axially fixed on said pin.

5. In an alligator shear in combination, an elongated bed, a pair of transversely spaced bearing bosses disposed intermediate the front and rear ends of the bed, a pin formed with a pair of spaced journals rotatably supported in bearings in the bosses, a lever arm axially and rotatably fixed, intermediate its ends, on said pin between the spaced journals, a stationary shear blade mounted on a portion of the bed extending-forwardly from and integrally formed with one of the bosses, said one boss being formed with a thrust surface at its outer face in a planenor- .mal to the axis of the .pin, a shear blade mounted on the forwardly extending .portion'ofthe lever arm adapted, when the lever is actuated, to'cooperate with the stationary blade in shearing relation, power means adapted to actuate the lever arm, and a thrust collar axially fixed on the pin engaging the said thrust surface.

6. In an alligator shear in combination, an elongated bed, a pair of transversely spaced bosses fixed on the bed, bores formed in the bosses, bushings removably mounted in the bores, a pin formed with spaced journals rotatably supported in said bushings, a lever arm axially fixed intermediate its ends on said pin between the spaced journals, a stationary shear blade mounted on the bed adjacent one of the bosses, a shear blade mounted on the lever arm adapted, when the lever is oscillated, to cooperate with the stationary blade in shearing relation, and power means adapted to oscillate the lever arm, said pin being substantially smaller in diameter than said bores and being provided with a removable collar larger in diameter than the bores and adapted to transmit axial thrust to the outer face of the boss adj acent the stationary shear blade, thereby to resist the transverse thrust resulting from the shearing action of the blades.

'7. In an alligator shear in combination, an elongated bed, a pair of transversely spaced bosses fixed on the bed, bores formed in the bosses, bushings formed with flanges engaging the outer faces of the bosses and removably mounted in the bores,

' a pin formed with spaced journals rotatably supmit axial thrust to the flange of the bushing mounted in the boss adjacent the stationary shear blade whereby said bushing resists the transverse thrust developed in the pin as a result of the shearing action of the blades.

8. In an alligator shear in combination, an elongated bed, a pair of transversely spaced bosses fixed on the bed, bores formed in the bosses,

bushings: formed: with flange the outer faces attheaho saes:andaremoimhly"mountedv in the hires; a; formed with-1 spaced Journals rota-tably. supported; in said. bushings; an: annular shoulder prolwided ozxithe; pin. which shoulder 'is larger in: diameter than. the' journals; and: is; posittiunedf. mtennediate the joumals. but: is smaller in diameter than thesborema lever unmounted, intmmediate' iits; ends, on'. said: pin: between the spaczdijoumlls and. formed withia. snapped; bore engaging the said shoulder, to resist axiat movementor. the lever arm; on the pim. a stationary shear blade.- mounted on the." bed adiacent. one of the bosses, a shear blademountedon the lever arm adapted, when the lever: is:oscillated-, to co.- operate with. the: stationary blade in. shearing: re:- lation, power'xneans: adapted to? oscillate the lever arm, the; said pinLheingformed with a; peripheral gmovemmmtingra; memorable. collar larger, indiameter thanthe; journals and adapted to; engage.

' 92.1mm. alligator shear-in oombinathm. an elmatedhed, anaitoi-tmnsrerselx-spacedbosm on the bed, bores ormed;in. the bosses. bushings mounted in the; bosses formed with flanges engaging the outer faces of the'bosamj pin formed: with spaced. journals: rotatabl: supported .in said bushinsaa lever arm; axially'flned intermediate its ends onsaid pin. between the spaced journals; a stationary shear blade. mountedon theebed. adjacenhone: of thebosses. a. shear blade; mounted on the. lever armadapted when theleverris; osmllated' to cooperate with the star tionarg blade in. shearing relation, power means adapted to oscillate thetlever arm, saidpin being ahle. collar and the. adjacent face of; the flange.

LAD Ll HERCIK. 

